Question

How many different arrangements of 3 letters can be formed if the First letter must be W or K

Answer 1

you would do 2 · 26 · 26 = 1,352 different arrangements 

Answer 2

Well if W is fixed then the second letter could be any of the 25 left over. for each of those 25 there is 24 possible other letters. So for one it should be 25X24. For 2 it should be 2X25X24. I think..